Robot inspection system

Abstract

To provide a robot inspection system that can prevent a variation of inspection environment and can prevent a variation and a reduction in inspection accuracy.SOLUTION: A robot inspection system has: a connection part to which a mounting table is connected on which a robot is mounted; a positioning mechanism that performs positioning of the mounting table with respect to the connection part; and an inspection unit that performs inspection of the robot, with the mounting table connected to the connection part. The mounting table is conveyed to the connection part by an automatic carrier vehicle. The inspection unit performs a plurality of types of inspection for the robot. The connection part has a recess including an entry port into which the mounting table enters, and the inspection unit is arranged around the recess.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a robotic inspection system. [Background technology]

[0002] Patent Document 1 describes a method for calibrating the origin of an articulated robot using a jig shaft. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 5-004179 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the origin calibration method for an articulated robot in Patent Document 1, the origin calibration is performed using a jig shaft at the location where the articulated robot to be inspected is placed, so the environment in which the articulated robot is placed may affect the inspection results, which may cause the accuracy of the origin calibration to fluctuate or decrease. [Means for solving the problem]

[0005] The robot inspection system of the present invention includes a connection section to which a mounting table on which a robot is mounted is connected; a positioning mechanism for positioning the connection portion and the mounting table; and an inspection unit that inspects the robot with the mounting table connected to the connection unit. [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a block diagram of a robotic inspection system according to a preferred embodiment. [Diagram 2] FIG. 2 is a side view showing an example of a robot inspected by the robot inspection system. [Diagram 3] FIG. 3 is an enlarged view of the robot shown in FIG. 2. [Figure 4] FIG. 2 is a side view showing the mounting table and the automated guided vehicle. [Diagram 5] FIG. 13 is a side view showing a state in which the mounting table is raised on the automatic transport vehicle. [Figure 6] FIG. 1 is a top view of a robotic inspection system. [Figure 7] FIG. 2 is a top view showing a state in which the mounting table is connected to the robot inspection system. [Figure 8] FIG. 13 is a diagram showing operations carried out in a second area. [Figure 9] FIG. 13 is a diagram showing operations carried out in a third area. [Figure 10] FIG. 13 is a diagram showing operations carried out in a third area. [Figure 11] FIG. 2 is a top view showing the first region. [Figure 12] FIG. [Figure 13] 11 is a perspective view showing a state in which the tip of the robot is positioned within a measurement area of ​​the sensor unit. FIG. [Figure 14] FIG. 4 is a diagram showing an example of an image acquired by a sensor unit. [Figure 15] FIG. 4 is a diagram showing an example of an image acquired by a sensor unit. [Figure 16] FIG. 4 is a diagram showing an example of an image acquired by a sensor unit. [Figure 17] FIG. 4 is a diagram showing an example of an image acquired by a sensor unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a robot inspection system according to the present invention will be described in detail based on the embodiments shown in the accompanying drawings.

[0008] FIG. 1 is a configuration diagram of a robot inspection system according to a preferred embodiment. FIG. 2 is a side view showing an example of a robot inspected by the robot inspection system. FIG. 3 is an enlarged view of the robot shown in FIG. 2. FIG. 4 is a side view showing a mounting table and an automatic guided vehicle. FIG. 5 is a side view showing a state in which the mounting table is lifted by the automatic guided vehicle. FIG. 6 is a top view of the robot inspection system. FIG. 7 is a top view showing a state in which the mounting table is connected to the robot inspection system. FIG. 8 is a diagram showing an operation performed in the second area. FIGS. 9 and 10 are respectively diagrams showing an operation performed in the third area. FIG. 11 is a top view showing the first area. FIG. 12 is a perspective view of a reference pin. FIG. 13 is a perspective view showing a state in which the tip of the robot is positioned within the measurement area of ​​the sensor unit. FIGS. 14 to 17 are respectively diagrams showing an example of an image acquired by the sensor unit.

[0009] As shown in Fig. 1, Fig. 6 to Fig. 11, three mutually orthogonal axes are illustrated as the X-axis, the Y-axis, and the Z-axis. In the following, the direction along the X-axis is also referred to as the X-axis direction, the direction along the Y-axis is also referred to as the Y-axis direction, and the direction along the Z-axis is also referred to as the Z-axis direction. The arrow side of each axis is also referred to as the plus side, and the opposite side is also referred to as the minus side. The Z-axis direction is aligned along the vertical direction.

[0010] The robot inspection system 1 shown in Fig. 1 is an apparatus that performs a predetermined inspection on a robot 3 that has been transported while placed on a mounting table 2. That is, instead of performing inspection for each robot 3 at the location where each robot 3 is installed as in the conventional method, all robots 3 are transported to the robot inspection system 1 for inspection. With such a system, all robots 3 can be inspected in the same location and in the same environment, making it difficult for the inspection accuracy to vary from robot to robot 3. Therefore, stable and highly accurate inspection can be performed on all robots 3.

[0011] The robot inspection system 1 will be described in detail below, but before that, a brief explanation will be given of the robot 3 to be inspected, the mounting table 2 on which the robot 3 is placed, and the automatic guided vehicle 4 (AGV: Automatic Guided Vehicle) that transports the mounting table 2 to the robot inspection system 1.

[0012] [Robot 3] 2, the robot 3 is a SCARA robot (horizontally articulated robot). The robot 3 has a base 30, a first arm 31 having a base end connected to the base 30 and rotating about a first rotation axis J1 that is aligned vertically to the base 30, and a second arm 32 having a base end connected to a tip end of the first arm 31 and rotating about a second rotation axis J2 that is aligned vertically to the first arm 31.

[0013] The robot 3 also has a working head 33 disposed at the tip of the second arm 32. The working head 33 has a spline nut 331 and a ball screw nut 332 disposed coaxially, and a spline shaft 333 inserted through the spline nut 331 and the ball screw nut 332. The spline shaft 333 is rotatable about a third rotation axis J3, which is the central axis of the second arm 32 and extends along the Z-axis direction, and is movable up and down along the third rotation axis J3.

[0014] The robot 3 also has a first joint drive mechanism 361 that connects the base 30 and the first arm 31 and rotates the first arm 31 relative to the base 30 around a first rotation axis J1, a second joint drive mechanism 362 that connects the first arm 31 and the second arm 32 and rotates the second arm 32 relative to the first arm 31 around a second rotation axis J2, a first head drive mechanism 363 that rotates the spline nut 331 to rotate the spline shaft 333 around a third rotation axis J3, and a second head drive mechanism 364 that rotates the ball screw nut 332 to raise and lower the spline shaft 333 in a direction along the third rotation axis J3.

[0015] Each of the drive mechanisms 361, 362, 363, and 364 has a motor as a drive source and a pulse encoder that detects the rotation of the motor. Therefore, the first joint drive mechanism 361 can detect the rotation angle of the first arm 31 about the first rotation axis J1 by counting the pulse signals output by the pulse encoder. The second joint drive mechanism 362 can detect the rotation angle of the second arm 32 about the second rotation axis J2 by ​​counting the pulse signals output by the pulse encoder. The first head drive mechanism 363 can detect the rotation angle of the spline shaft 333 about the third rotation axis J3 by counting the pulse signals output by the pulse encoder. The second head drive mechanism 364 can detect the height of the spline shaft 333 in the Z-axis direction by counting the pulse signals output by the pulse encoder.

[0016] The robot 3 also has a robot controller 37 that independently controls each of the drive mechanisms 361, 362, 363, and 364 based on position commands from a host computer (not shown). The robot controller 37 is, for example, composed of a computer, and has a processor that processes information, a memory communicatively connected to the processor, and an external interface that connects to an external device. Various programs that can be executed by the processor are stored in the memory, and the processor can read and execute the various programs stored in the memory.

[0017] As shown in FIG. 3, the robot 3 has a cover 34 disposed on the underside of the second arm 32 and covering the gap between the second arm 32 and the spline shaft 333. A downward triangular marker 341 is formed on the cover 34 and is used in the inspection described below. The marker 341 can be formed by printing, pasting, embossing, or the like. However, the configuration of the marker 341 is not particularly limited as long as it can be used in the inspection described below. In addition, if the shape of the cover 34 has a unique part, that part may be used as the marker 341.

[0018] The robot 3 also has a stopper 35 disposed midway along the spline shaft 333. When the stopper 35 comes into contact with the cover 34, the spline shaft 333 is restricted from moving any further upward. The stopper 35 is a C-shaped member having both ends connected by a screw N1, and is fixed to the spline shaft 333 by tightening the screws. When the stopper 35 is fixed to the spline shaft 333, both ends of the stopper 35 are spaced apart from each other, forming a gap 350 therebetween. The gap 350 functions as a positioning mark used in the inspection described below. However, the configuration of the stopper 35 is not particularly limited as long as it can exert the above-mentioned effects.

[0019] The above describes the robot 3. However, there is no particular limitation on the configuration of the robot 3. For example, the robot 3 may be a robot other than a SCARA robot, specifically a six-axis articulated robot, a dual-arm robot, or the like.

[0020] [Placement table 2] As shown in FIG. 4, the mounting table 2 has a top plate portion 21 on which the robot 3 is placed and fixed, a bottom plate portion 22 located below the top plate portion 21, and four legs 23 supporting the top plate portion 21 and the bottom plate portion 22. The four legs 23 are located at the four corners of the top plate portion 21 and the bottom plate portion 22, and support them in a well-balanced manner. In FIG. 4, only the two legs 23 on the front side are shown, but two legs 23 are similarly arranged on the back side. In addition, casters 24 are attached to the lower end of each leg portion 23, and the mounting table 2 can be freely moved by rotating the casters 24. Such a mounting table 2 may be, for example, a work table for assembling the robot 3, or an installation table for installing the robot 3 at a predetermined location.

[0021] The above describes the mounting table 2. However, the configuration of the mounting table 2 is not particularly limited as long as it is possible to mount the robot 3 thereon, and for example, the casters 24 may be omitted.

[0022] [Automated guided vehicle 4] As shown in Fig. 4, the automated guided vehicle 4 has a platform 41 on which the platform 2 is placed, a lifting device 42 for raising and lowering the platform 41, wheels 43, a motor 44 for driving the wheels 43, and a controller 45 for controlling the driving of the motor 44. As shown in Fig. 5, the automated guided vehicle 4 slips under the bottom plate portion 22 of the platform 2 with the platform 41 lowered, and then raises the platform 41 with the lifting device 42, thereby lifting the platform 2 so as to support the bottom plate portion 22 from below. The automated guided vehicle 4 also receives instructions on a travel route from a management device (not shown) and travels according to the received travel route.

[0023] By using such an automatic guided vehicle 4, the robot 3 can be automatically transported together with the mounting table 2 to the robot inspection system 1. This eliminates the need for an operator to push the mounting table 2 to the robot inspection system 1, for example, thereby reducing manpower and enabling the inspection of the robot 3 to be carried out smoothly.

[0024] The above describes the automated guided vehicle 4. However, the configuration of the automated guided vehicle 4 is not particularly limited as long as it can transport the robot 3 together with the mounting table 2 to the robot inspection system 1. Also, the automated guided vehicle 4 may be omitted, and the worker may push the mounting table 2 himself to transport it to the robot inspection system 1.

[0025] [Robot Inspection System 1] As shown in FIG. 1, the robot inspection system 1 is placed in an inspection room 10 maintained in a predetermined environment. This allows inspection of multiple robots 3 under the same conditions, further improving the inspection accuracy. In addition, a vibration damping member 11 is placed between the floor of the inspection room 10 and the robot inspection system 1. This makes it difficult for external vibrations to be transmitted to the robot inspection system 1 through the floor, further improving the inspection accuracy. In this embodiment, a metal plate, particularly an iron plate, is used as the vibration damping member 11. In addition, this iron plate is fixed to the floor by an anchor, and the robot inspection system 1 is fixed to the iron plate by an anchor. However, the installation location of the robot inspection system 1 is not particularly limited. In addition, the vibration damping member 11 may be omitted, and the robot inspection system 1 may be installed directly on the floor.

[0026] As shown in FIG. 6, the robot inspection system 1 also has a connection section 5 to which the mounting table 2 is connected, a positioning mechanism 6 that positions the mounting table 2 with respect to the connection section 5, and an inspection section 7 that inspects the robot 3.

[0027] The connection part 5 has a recess 51 with an entrance 511 through which the mounting table 2 enters, as viewed in a plan view from the Z-axis direction. In this embodiment, the entrance 511 is located on the negative side of the connection part 5 in the Y-axis direction. The inspection part 7 is arranged around the recess 51. By arranging the inspection part 7 around the connection part 5 in this manner, the inspection of the robot 3 can be efficiently performed. In particular, since the robot 3 is a SCARA robot and the first and second arms 31 and 32 move only in the horizontal direction, by arranging the inspection part 7 around the recess 51, the inspection part 7 can be efficiently arranged within the movable range of the SCARA robot, and can be specialized for the inspection of the robot 3. However, the arrangement of the inspection part 7 is not particularly limited.

[0028] Further, a positioning mechanism 6 is disposed in the recess 51. The positioning mechanism 6 positions the mounting table 2 transported into the recess 51 with respect to the connection portion 5. This determines the position of the robot 3 with respect to the robot inspection system 1. Therefore, all the robots 3 can be disposed at the same position, improving the inspection accuracy. The positioning mechanism 6 of this embodiment has a pair of abutment portions 61, 62 protruding into the recess 51. As shown in FIG. 7, the mounting table 2 is positioned with respect to the connection portion 5 by abutting the abutment portions 61, 62. However, the configuration of the positioning mechanism 6 is not particularly limited as long as it can position the mounting table 2 with respect to the connection portion 5.

[0029] The inspection unit 7 performs a predetermined inspection of the robot 3 on the mounting table 2 connected to the connection unit 5. In this specification, "inspection" is meant to include all actions necessary for the setting, maintenance, etc. of the robot 3, such as various checks, various maintenance, various preparations, various measurements, and various calibrations, in addition to inspection.

[0030] Furthermore, the inspection unit 7 performs a plurality of types of inspections on the robot 3. In this manner, the robot inspection system 1 can perform a plurality of types of inspections on the robot 3, and therefore can perform the inspections of the robot 3 collectively and smoothly. As shown in Fig. 6, the inspection unit 7 has a first region S1 located on the positive side of the recess 51 in the Y-axis direction, a second region S2 located on the negative side of the first region S1 in the X-axis direction, and a third region S3 located on the positive side of the first region S1 in the X-axis direction.

[0031] Of these areas S1, S2, and S3, the second area S2 is an area where preparations for the inspection in the first area S1 are made. In the second area S2, an operation of attaching a weight M to the spline shaft 333 is performed. As shown in Fig. 6, the second area S2 is provided with the weight M, a tool T for fixing the weight M to the spline shaft 333, and a moving mechanism 80 for moving the tool T.

[0032] In this embodiment, two weights M of different weights are arranged, and the weight M to be attached to the spline shaft 333 can be selected according to the carrying capacity of the robot 3 to be inspected. Each weight M is cylindrical with a through hole into which the spline shaft 333 is inserted. As shown in FIG. 8, each weight M has a screw hole that penetrates the side surface and the through hole, and a screw N2 is screwed into this screw hole. The tool T is, for example, a screwdriver that turns the screw N2, and the screw N2 is turned with the spline shaft 333 inserted into the through hole, and the screw N2 is pressed against the spline shaft 333 to fix the weight M to the spline shaft 333.

[0033] The second area S2 has been described above. However, the configuration of the second area S2 is not particularly limited. For example, the number and shape of the weights M, the method of attaching the weights M to the spline shaft 333, etc. are not particularly limited. In addition, the work performed in the second area S2 is also not particularly limited, and can be appropriately set based on various conditions required of the robot 3, the work performed in the other areas S1 and S3, etc. In addition, the second area S2 may be omitted.

[0034] The third area S3 is an area where origin calibration of the third rotation axis J3 is performed. The origin calibration of the third rotation axis J3 refers to the operation of matching the origin of the third rotation axis J3 stored in the robot controller 37 (hereinafter also referred to as the "ideal origin") with the actual origin (hereinafter also referred to as the "actual origin") when the third rotation axis J3 is positioned at the ideal origin under the control of the robot controller 37. The ideal origin refers to a state in which each motor of the first and second head drive mechanisms 363 and 364 is in a predetermined position (hereinafter referred to as the "0 pulse position"). However, the method of setting the origin of the third rotation axis J3 is not particularly limited.

[0035] As shown in Figures 9 and 10, a rotation angle calibration unit 81 that calibrates the rotation angle of the spline shaft 333 and a height calibration unit 82 that calibrates the height of the spline shaft 333 are arranged in the third region S3.

[0036] 9, the rotation angle calibration unit 81 uses an image recognition technique to calibrate the rotation angle of the spline shaft 333. The rotation angle calibration unit 81 has a camera 811 that captures an image of the spline shaft 333 in the horizontal direction, from the positive side in the X-axis direction in the illustrated configuration, a movement mechanism 813 that moves the camera 811 in the X-axis direction and the Z-axis direction, and a processing unit 812 that uses the image captured by the camera 811 (hereinafter referred to as the "acquired image") to determine the amount of deviation (deviation) between the ideal origin and the actual origin.

[0037] The processing unit 812 stores a large number of comparison images in which the rotation angles of the spline shaft 333 from the ideal origin are different from one another and known. The processing unit 812 then calibrates the rotation angle of the spline shaft 333 by comparing these comparison images with the acquired image captured by the camera 811 using a template matching technique.

[0038] Specifically, first, the motor of the first head driving mechanism 363 is set to the 0 pulse position using the robot controller 37. Next, the camera 811 captures the state in which the marker 341 and the gap 350 between the stopper 35 are in the field of view to obtain an acquired image. Next, the processing unit 812 performs template matching on the acquired image with a number of comparison images, and extracts one comparison image that has the highest similarity to the acquired image from among them. Then, the rotation angle from the ideal origin corresponding to the extracted comparison image is determined as the rotation offset value of the third rotation axis J3. Then, the determined rotation offset value of the third rotation axis J3 is set in the robot controller 37. With the above, the rotation angle calibration work of the third rotation axis J3 is completed. However, the method of calibrating the rotation angle of the third rotation axis J3 is not particularly limited.

[0039] As shown in Figure 10, the height calibration unit 82 has a pair of contact-type distance sensors 821, 822, a moving mechanism 824 that moves the pair of contact-type distance sensors 821, 822 in the X-axis and Z-axis directions, and a processing unit 823 that calculates the amount of deviation (deviation) between the ideal origin and the actual origin based on the output of the contact-type distance sensors 821, 822.

[0040] The contact type distance sensors 821 and 822 can accurately measure the amount of pressing of the tip. For example, Keyence Corporation's "General-purpose contact type digital sensor / GT series" can be suitably used as such contact type distance sensors 821 and 822. These contact type distance sensors 821 and 822 are arranged apart from each other in the Z-axis direction and both face upward.

[0041] In the height calibration operation, first, the motor of the second head driving mechanism 364 is set to the 0 pulse position using the robot controller 37. Next, the contact type distance sensor 821 is brought into contact with the lower surface of the second arm 32, and the contact type distance sensor 822 is brought into contact with the tip of the spline shaft 333. Next, the processing unit 823 calculates the actual distance (hereinafter also referred to as the "actual distance") between the lower surface of the second arm 32 and the tip of the spline shaft 333 from the separation distance of the contact type distance sensors 821 and 822 and their output values. The processing unit 823 also stores the ideal distance (hereinafter also referred to as the "ideal distance") between the lower surface of the second arm 32 and the tip of the spline shaft 333 when the motor of the second head driving mechanism 364 is in the 0 pulse position, and determines the deviation amount between the actual distance and the ideal distance as the height offset value of the third rotation axis J3. Then, the determined height offset value of the third rotation axis J3 is set in the robot controller 37. With the above, the height calibration operation of the third rotation axis J3 is completed. However, the method of calibrating the height of the third rotation axis J3 is not particularly limited.

[0042] The third area S3 has been described above. However, the configuration of the third area S3 is not particularly limited. For example, one of the rotation angle calibration unit 81 and the height calibration unit 82 may be omitted. In addition, the work performed in the third area S3 is not particularly limited, and can be appropriately set based on various conditions required of the robot 3, the work performed in the other areas S1 and S2, etc. In addition, the third area S3 may be omitted.

[0043] The first area S1 is an area where origin calibration of the first and second rotation axes J1, J2, height inspection of the spline shaft 333, inspection of height deviation between the left and right hand systems, repeatability inspection, etc. are performed.

[0044] As shown in FIG. 11, the first area S1 includes a stage 90 movable in the Y-axis direction relative to the connection part 5, a calibration device 94 including a reference pin 91 and a pair of sensor units 92 and 93 arranged on the stage 90, and a processing unit 95 for processing images captured by the sensor units 92 and 93. By arranging the calibration device 94 on the stage 90, the distance between the connection part 5 and the calibration device 94 becomes variable, so that it is possible to accommodate robots 3 of various sizes. Therefore, the versatility of the robot inspection system 1 is improved. In addition, by moving the stage 90 to the Y-axis positive side and away from the connection part 5 when connecting the mounting table 2 to the connection part 5, it is possible to avoid a collision between the calibration device 94 and the robot 3. Therefore, it is possible to suppress breakdowns and damage to the robot inspection system 1 and the robot 3.

[0045] However, the present invention is not limited to this, and the stage 90 may be fixed and unable to move in the Y-axis direction, or may be configured so that the stage 90 can also move in the X-axis direction.

[0046] The reference pin 91 is disposed at the center of the stage 90. As shown in FIG. 12, the reference pin 91 is a column extending in the Z-axis direction, and is L-shaped bent at a right angle in a plan view from the Z-axis direction. The reference pin 91 has a first outer surface 911 and a second outer surface 912 that are perpendicular to each other. As shown in FIG. 11, a normal Q1 of the first outer surface 911 and a normal Q2 of the second outer surface 912 are inclined at 45° with respect to the X-axis and the Y-axis, respectively. Such a reference pin 91 is a pin that serves as a reference for origin calibration, and its position coordinates in the robot coordinate system are known. The reference pin 91 is formed with sufficiently high dimensional accuracy. However, the shape of the reference pin 91 is not particularly limited as long as it can be used in the inspection described later. The material of the reference pin 91 is not particularly limited, and for example, various metal materials, various resin materials, various glass materials, etc. can be used.

[0047] 11, a pair of sensor units 92, 93 are arranged in a cross shape so that their optical axes O1, O2 are perpendicular to each other, and a reference pin 91 is located at the intersection of the optical axes O1, O2. In addition, the optical axis O1 of the sensor unit 92 coincides with the normal line Q1, and the optical axis O2 of the sensor unit 93 coincides with the normal line Q2.

[0048] The sensor unit 92 is a dimension measuring instrument, and has a light emitting device 921 and a light receiving device 922 arranged opposite to each other via the reference pin 91. The light emitting device 921 and the light receiving device 922 are arranged facing each other along the normal line Q1. The light emitting device 921 emits light toward the light receiving device 922. The light emitting device 921 has a green LED 921a as a light source, and emits green light from the green LED as uniform parallel light LL1 using a lens. On the other hand, the light receiving device 922 has an image pickup element 922a such as a CCD or CMOS. When performing origin calibration of the first and second rotation axes J1 and J2, the measurement area (field of view) of the image pickup element 922a includes the tip of the reference pin 91 and the tip of the spline shaft 333 (hereinafter also referred to as the "tip of the robot 3"). Therefore, the light receiving device 922 captures a silhouette image of these, that is, an image in which the reference pin 91 and the spline shaft 333 are reflected as shadows. That is, since the light emitting device 921 is of a transmitted illumination type, it is possible to avoid the occurrence of halation even if the measurement object is made of metal, and it is possible to clearly observe the contour.

[0049] The sensor unit 93 has the same configuration as the sensor unit 92 described above. That is, the sensor unit 93 has a light emitting device 931 and a light receiving device 932 arranged opposite to each other via a reference pin 91. The light emitting device 931 and the light receiving device 932 are arranged along a normal line Q2. The light emitting device 931 emits light toward the light receiving device 932. The light emitting device 931 includes a green LED 931a as a light source, and converts green light from the green LED into uniform parallel light LL2 using a lens and emits it. On the other hand, the light receiving device 932 includes an imaging element 932a such as a CCD or a CMOS.

[0050] Although there is no particular limitation to such sensor units 92 and 93, the "2D High Speed ​​Optical Sensor / TM Series" manufactured by Keyence Corporation, particularly the "TM-6050" can be suitably used. This provides excellent measurement accuracy and enables highly accurate origin calibration of the first and second rotation axes J1 and J2.

[0051] In order to improve the accuracy of the origin calibration of the first and second rotation axes J1 and J2, it is important to precisely orthogonally arrange the sensor units 92 and 93. In this embodiment, the sensor units 92 and 93 are positioned as follows. As described above, the sensor unit 92 captures a silhouette image of the reference pin 91. Here, when the optical axis O1 coincides with the normal line Q1, the width dimension of the reference pin 91 on the image acquired by the light receiving device 922 is smallest, and the more the optical axis O1 is inclined from the normal line Q1, the larger the width dimension of the reference pin 91 on the image. Therefore, the sensor unit 92 is arranged so that the width dimension of the reference pin 91 on the image acquired by the light receiving device 922 is smallest. Similarly, the sensor unit 93 is arranged so that the width dimension of the reference pin 91 on the image acquired by the light receiving device 932 is smallest. As described above, since the normal lines Q1 and Q2 are mutually orthogonal, this method allows the sensor units 92 and 93 to be precisely orthogonally arranged. However, the method for positioning the sensor units 92 and 93 is not particularly limited.

[0052] Next, various inspections performed in the first area S1 will be described in order. Note that, as described above, the various inspections performed in the first area S1 are performed in a state where the weight M is attached to the spline shaft 333.

[0053] In the first area S1, origin calibration of the first and second rotation axes J1 and J2 is performed. The origin calibration of the first rotation axis J1 refers to the operation of matching the origin of the first rotation axis J1 stored in the robot controller 37 (hereinafter also referred to as the "ideal origin") with the actual origin (hereinafter also referred to as the "actual origin") when the first rotation axis J1 is positioned at the ideal origin under the control of the robot controller 37. The ideal origin refers to a state in which the motor of the first joint drive mechanism 361 is in a predetermined position (hereinafter referred to as the "0 pulse position"). Similarly, the origin calibration of the second rotation axis J2 refers to the operation of matching the origin of the second rotation axis J2 stored in the robot controller 37 (hereinafter also referred to as the "ideal origin") with the actual origin (hereinafter also referred to as the "actual origin") when the second rotation axis J2 is positioned at the ideal origin under the control of the robot controller 37. The ideal origin refers to a state in which the motor of the second joint drive mechanism 362 is in a predetermined position (hereinafter referred to as the "0 pulse position").

[0054] In the origin calibration of the first and second rotation axes J1 and J2, first, the stage 90 is moved to place the reference pin 91 at a reference position that is a predetermined coordinate in the robot coordinate system. The reference position in this embodiment is located directly below the central axis of the spline shaft 333 when the motors of the first and second joint drive mechanisms 361 and 362 are both set to the 0 pulse position. However, the reference position is not particularly limited. Next, the motors of the first and second joint drive mechanisms 361 and 362 are both set to the 0 pulse position using the robot controller 37. Next, the second head drive mechanism 364 is moved to lower the spline shaft 333, and the tip of the spline shaft 333 is positioned within the measurement area of ​​the sensor units 92 and 93, as shown in FIG. 13. If there is no deviation between the ideal origin and the real origin, in this state, the spline shaft 333 is positioned directly above the reference pin 91.

[0055] Next, this state is imaged by the light receiving device 922 to obtain an image G1 as shown in FIG. 14, and is also imaged by the light receiving device 932 to obtain an image G2 as shown in FIG. 15. The timing of image capture by the light receiving devices 922 and 932 is not particularly limited, and may be simultaneous or different. In the example of FIG. 14 and FIG. 15, the third rotation axis J3, which is the central axis of the spline shaft 333, is shifted in the lateral direction of the image with respect to the central axis Jp of the reference pin 91, and a shift occurs between the ideal origin and the real origin in at least one of the first and second rotation axes J1 and J2. In this way, when the third rotation axis J3 is shifted with respect to the central axis Jp in at least one of the images G1 and G2, the third rotation axis J3 is made to coincide with the central axis Jp in each of the images G1 and G2 as shown in FIG. 16 and FIG. 17 while repeating the driving of the first and second joint drive mechanisms 361 and 362 and the image capture by the light receiving devices 922 and 932.

[0056] Next, the processing unit 95 stores the positions of the motors of the first and second joint drive mechanisms 361 and 362 when the third rotation axis J3 coincides with the central axis Jp as actual positions. Next, the processing unit 95 calculates the deviation between the actual position of the motor of the first joint drive mechanism 361 and the 0 pulse position, and determines the calculated deviation as the offset value of the first rotation axis J1. Similarly, the processing unit 95 calculates the deviation (deviation) between the actual position of the motor of the second joint drive mechanism 362 and the 0 pulse position, and determines the calculated deviation as the offset value of the second rotation axis J2. Then, for example, the worker sets the offset values ​​of the first and second rotation axes J1 and J2 determined by the processing unit 95 in the robot controller 37. With the above, the origin calibration of the first and second rotation axes J1 and J2 is completed. The robot controller 37 controls the driving of the first and second joint drive mechanisms 361 and 362 so that the real origin coincides with the ideal origin based on the set offset value. This enables highly accurate control of the robot 3.

[0057] Furthermore, in the first area S1, a height inspection is performed on the spline shaft 333. For example, when assembling the robot 3, the mounting position of the second head driving mechanism 364 may shift, and the height of the spline shaft 333 may accordingly shift from the design. Therefore, in this embodiment, the height deviation of the spline shaft 333 is inspected.

[0058] Specifically, first, the motor of the second head driving mechanism 364 is set to a preset measurement position, and the tip of the spline shaft 333 is positioned within the measurement area of ​​the sensor units 92, 93. Next, the processing unit 95 images this state with at least one of the sensor units 92, 93, and calculates the Z-axis position coordinate (hereinafter also referred to as the "actual position coordinate") of the tip of the spline shaft 333 based on the obtained image. The processing unit 95 previously stores the Z-axis position coordinate (hereinafter also referred to as the "ideal position coordinate") of the tip of the spline shaft 333 at the measurement position in an ideal state where there is no deviation in the mounting position of the second head driving mechanism 364, and measures the height deviation of the spline shaft 333 from the actual position coordinate and the ideal position coordinate.

[0059] Furthermore, in the first region S1, a height deviation inspection of the left and right arm systems is performed. For example, even if the tip of the spline shaft 333 (hereinafter also referred to as the "tip of the robot 3") is positioned at the same coordinate in the robot coordinate system, there may be a difference in height of the tip of the robot 3 between the posture of the right arm system in which the first and second arms 31, 32 are bent on the positive side in the X-axis direction and the posture of the left arm system in which they are bent on the negative side in the X-axis direction. Therefore, in this embodiment, the height deviation of the left and right arm systems is inspected.

[0060] Specifically, first, a target coordinate to which the tip of the robot 3 is to be moved is determined. The target coordinate is a coordinate within the measurement area of ​​the sensor units 92 and 93. Next, the robot 3 is moved to move the tip of the robot 3 to the target coordinate in the left arm system posture, and the state is imaged by at least one of the sensor units 92 and 93 to obtain a left arm system image. Next, the robot 3 is moved to move the tip of the robot 3 to the target coordinate in the right arm system posture, and the state is imaged by at least one of the sensor units 92 and 93 to obtain a right arm system image. Next, the height deviation between the left arm system and the right arm system is measured based on the Z-axis position coordinate of the tip of the robot 3 calculated from the left arm system image and the Z-axis position coordinate of the tip of the robot 3 calculated from the right arm system image.

[0061] Furthermore, in the first area S1, the repeatability characteristic of the robot 3 is inspected. The repeatability indicates the degree of reproducibility when the same operation is repeatedly performed, and the better the repeatability characteristic, the higher the accuracy of the robot 3. Specifically, first, a first target coordinate and a second target coordinate, both of which are located within the measurement areas of the sensor units 92 and 93, are set, and the robot 3 is moved so that the tip of the robot 3 moves back and forth between the first target coordinate and the second target coordinate. Then, every time the tip of the robot 3 reaches the first and second target coordinates, an image of the state is taken by at least one of the sensor units 92 and 93. Then, the amount of deviation from the first and second target coordinates is measured from each of the obtained images, and the repeatability of the robot 3 is measured using the maximum and average values ​​of the deviation.

[0062] Furthermore, in the first region S1, the length L1 of the first arm 31 and the length L2 of the second arm 32 are measured. As shown in FIG. 2, the length L1 is the distance between the first rotation axis J1 and the second rotation axis J2, and the length L2 is the distance between the second rotation axis J2 and the third rotation axis J3. Depending on the assembly accuracy of the robot 3, the actual lengths L1 and L2 may deviate from the designed lengths L1 and L2. Even in this case, for example, in a PTP (Point to Point) movement in which the tip of the robot 3 is moved from one coordinate to another coordinate, the trajectory is not important, so problems are unlikely to occur. However, for example, when the tip of the robot 3 is moved from one coordinate to another coordinate on a determined trajectory, if the lengths L1 and L2 deviate from the design values, the robot will meander with respect to the determined trajectory, and the CP (Continuous Path) accuracy will deteriorate. Therefore, in this embodiment, the lengths L1 and L2 of the first and second arms 31 and 32 are measured to suppress deterioration of the CP accuracy.

[0063] Specifically, first, the robot 3 is set to a first posture in which its tip is located within the measurement area of ​​the sensor units 92 and 93, and this state is imaged by the sensor units 92 and 93 to obtain a first posture image. Next, the robot 3 is set to a second posture by moving only the motor of the first joint drive mechanism 361 by a predetermined angle within a range in which the tip of the robot 3 does not deviate from the measurement area of ​​the sensor units 92 and 93, and this state is imaged by the sensor units 92 and 93 to obtain a second posture image. The processing unit 95 calculates the length L1 of the first arm 31 based on the rotation angle of the motor of the first joint drive mechanism 361 and the position coordinates before and after the movement of the tip of the robot 3 identified from the first and second posture images. Next, the robot 3 is set to the first posture again. Then, the robot 3 is set to a third posture by moving only the motor of the second joint drive mechanism 362 by a predetermined angle within a range in which the tip of the robot 3 does not deviate from the measurement area of ​​the sensor units 92 and 93, and this state is imaged by the sensor units 92 and 93 to obtain a third posture image. The processing unit 95 measures the length L2 of the second arm 32 based on the rotation angle of the motor of the second joint drive mechanism 362 and the position coordinates before and after the movement of the tip of the robot 3 identified from the first and third posture images. Then, for example, the worker sets the lengths L1 and L2 measured by the processing unit 95 in the robot controller 37. The robot controller 37 calculates the position of the tip of the robot 3 based on the set lengths L1 and L2. This enables high-precision control of the robot 3.

[0064] The above describes the inspections performed in the first area S1. However, the method of each inspection is not particularly limited. In addition, the inspections performed in the first area S1 are not particularly limited, and as long as the origin calibration of the robot 3 can be performed, the other inspections are not particularly limited, and at least one of the above-mentioned inspection contents may be omitted, or an inspection different from the above-mentioned inspection contents may be performed.

[0065] The above describes the robot inspection system 1. As described above, such a robot inspection system 1 has the connection unit 5 to which the mounting table 2 on which the robot 3 is placed is connected, the positioning mechanism 6 for positioning the connection unit 5 and the mounting table 2, and the inspection unit 7 for inspecting the robot 3 with the mounting table 2 connected to the connection unit 5. In such a robot inspection system 1, the robot 3 transported to the robot inspection system 1 is inspected, so all the robots 3 can be inspected in the same place and in the same environment. Therefore, stable and highly accurate inspection can be performed on all the robots 3.

[0066] As described above, the mounting table 2 is transported to the connection section 5 by the automatic transport vehicle 4. This allows the robot 3 to be automatically transported together with the mounting table 2 to the robot inspection system 1. Therefore, for example, it is no longer necessary for an operator to push the mounting table 2 to move it to the robot inspection system 1, which reduces manpower and allows the inspection of the robot 3 to be carried out smoothly.

[0067] As described above, the inspection unit 7 performs a plurality of types of inspections on the robot 3. This allows the inspection of the robot 3 to be carried out smoothly.

[0068] As described above, the connection part 5 has the recess 51 with the entrance 511 through which the mounting table 2 enters, and the inspection part 7 is disposed around the recess 51. As a result, the inspection part 7 is located around the robot 3, in other words, the robot 3 is located at the center of the inspection part 7, so that the inspection of the robot 3 can be performed efficiently.

[0069] As described above, the robot 3 is a SCARA robot having the base 30, the first arm 31 that rotates about the first rotation axis J1 relative to the base 30, the second arm 32 that rotates about the second rotation axis J2 relative to the first arm 31, and the work head 33 disposed on the second arm 32. In the robot inspection system 1, the inspection unit 7 is disposed around the recess 51, so that the robot inspection system 1 can be specialized for inspection of the SCARA robot.

[0070] As described above, the inspection unit 7 has the calibration device 94 that calibrates the first rotation axis J1 and the second rotation axis J2. This allows the robot inspection system 1 to calibrate the first rotation axis J1 and the second rotation axis J2.

[0071] As described above, the calibration device 94 moves in the Y-axis direction, which is the horizontal direction. This allows the distance between the connection unit 5 and the calibration device 94 to be variable, making it possible to accommodate robots 3 of various sizes. This increases the versatility of the robot inspection system 1. Furthermore, by keeping the calibration device 94 away from the connection unit 5 when connecting the mounting table 2 to the connection unit 5, it is possible to avoid a collision between the calibration device 94 and the robot 3. This makes it possible to suppress breakdowns and damage to the robot inspection system 1 and the robot 3.

[0072] Although the robot inspection system of the present invention has been described above based on the illustrated embodiment, the present invention is not limited to this. The configuration of each part can be replaced with any configuration having a similar function. In addition, any other configuration may be added to the present invention. [Explanation of symbols]

[0073] 1...robot inspection system, 10...inspection chamber, 11...vibration damping member, 2...mounting table, 21...top plate portion, 22...bottom plate portion, 23...leg portion, 24...caster, 3...robot, 30...base, 31...first arm, 32...second arm, 33...work head, 331...spline nut, 332...ball screw nut, 333...spline shaft, 34...cover, 341...marker, 35...stopper, 350...gap, 361...first joint Driving mechanism, 362... second joint driving mechanism, 363... first head driving mechanism, 364... second head driving mechanism, 37... robot controller, 4... automatic guided vehicle, 41... platform, 42... lifting device, 43... wheels, 44... motor, 45... controller, 5... connection part, 51... recess, 511... entry port, 6... positioning mechanism, 61... abutment part, 62... abutment part, 7... inspection part, 80... movement mechanism, 81... rotation angle calibration part, 811... camera, 812 ...processing unit, 813...movement mechanism, 82...height calibration unit, 821...contact type distance sensor, 822...contact type distance sensor, 823...processing unit, 824...movement mechanism, 90...stage, 91...reference pin, 911...first outer surface, 912...second outer surface, 92...sensor unit, 921...light emitting device, 921a...green LED, 922...light receiving device, 922a...imaging element, 93...sensor unit, 931...light emitting device, 931a...green LED, 9 32...light receiving device, 932a...image sensor, 94...calibration device, 95...processing unit, G1...image, G2...image, G3...image, G4...image, J1...first rotation axis, J2...second rotation axis, J3...third rotation axis, Jp...central axis, L1...length, L2...length, LL1...parallel light, LL2...parallel light, M...weight, N1...screw, N2...screw, O1...optical axis, O2...optical axis, Q1...normal, Q2...normal, S1...first region, S2...second region, S3...third region, T...tool

Claims

1. a connection portion to which a platform on which the robot is placed is connected; a positioning mechanism for positioning the connection portion and the mounting table; an inspection unit that inspects the robot with the mounting table connected to the connection unit.

2. The robot inspection system according to claim 1 , wherein the mounting table is transported to the connection portion by an automatic guided vehicle.

3. The robot inspection system according to claim 1 , wherein the inspection unit performs a plurality of types of inspections on the robot.

4. the connection portion has a recess having an entrance through which the mounting table enters, The robot inspection system according to claim 1 , wherein the inspection unit is disposed around the recess.

5. 2. The robot inspection system of claim 1, wherein the robot is a SCARA robot having a base, a first arm that rotates relative to the base about a first rotation axis, a second arm that rotates relative to the first arm about a second rotation axis, and a work head disposed on the second arm.

6. The robot inspection system according to claim 5 , wherein the inspection unit has a calibration device that calibrates the first rotation axis and the second rotation axis.

7. The robotic inspection system of claim 6 , wherein the calibration device moves horizontally.

Images